Automatic coner machines are an example of textile machines which have many winding stations which are positioned side by side. When yarns are unwound from pirns and are collected on a cross-turn package, they are called "cones". These cones are used in the following process steps.
During transfer, the yarn is treated to remove defects which appear in even the best spun yarns. This defect removing operation is conducted by the slub catcher. The slub catcher detects defects such as large-diameter lengths, weak points, button holes, loops, and etc. After the slub catcher detects a defect, it simultaneously cuts the yarn, stops the winding, and starts the knotting cycle. In this way, the defects that existed in the yarn are removed and replaced with knots. To make a knot an automatic device must intervene in the process. Any intervention stops the cone winding step and necessarily results in a decrease in process efficiency.
Tensioning the yarn during the winding step is known to be important because successful cone winding is largely dependent on its careful regulation. Some units which control the tension do so by applying constant tension to the feed yarn during all of the steps of the cone winding process. It is realized and understood by those skilled in the art that the tension applied to the yarn during the cone winding process is not only supplied by the tensioning units but also, to a large extent, by the winding speed. When the knotting and doffing steps occur they stop the yarn feed and consequently decrease the tension on the yarn to zero. The tension on the yarn approaches zero because the winding speed no longer contributes to supplying any tension.
In the segment of yarn between the pirn and the yarn tensioning disks, yarns which are slack or free at their ends may wind upon themselves and form loops. Then, during the restarting step of the cone winding unit, the slub catcher detects this loop as an irregularity and again intervenes thereby stopping the winding process another time. Not only does this drawback occur in the devices of the prior art but, in addition, when yarns which are more slippery are used, the feed yarn end feed nozzle suctions a longer yarn length than necessary thus causing a considerable waste of yarn.
The device of the applicants overcomes these drawbacks and solves these problems experienced by the devices of the prior art.